摘要:
用密度泛函理论中的UB3LYP方法，研究了单重态和三重态势能面自旋禁阻反应Th(6d27S2) + C2H4→ThH3-CCH的微观机理。找到了两条反应通道，对其中涉及的两态反应(TSR)进行了分析。进而运用Hammond假设和Yoshizawa等的内禀坐标单点垂直激发计算的方法找出了一系列势能面交叉点[crossing points (CPs)]，并作了相应的讨论。通过计算，讨论了势能面交叉和可能的自旋翻转过程。用Harvey等的方法优化出最低能量交叉(MECP)，进一步讨论了Th与C2H4的反应中不同势能面之间的“系间窜越”(ISC)的可能性。最后，对前线分子轨道MECP2做了简单的讨论，这些理论结果可以作为进一步理论研究和实验的指导。
Abstract:
Using UB3LYP method in density functional theory, the micro mechanism of the singlet and triplet potential energy surfaces of the three spin forbidden reactions Th(6d27S2) + C2H4→ThH3-CCH was investigated. Two reaction channels were found, and the two state reaction (TSR) was analyzed. Then we used the method of single point vertical excitation calculation of intrinsic coordinates Hammond and Yoshizawa’s hypothesis, found a series of potential energy surface crossing point of [crossing points (CPs)], and made the corresponding discussion. By calculation, the crossover of potential energy surface and the spin flip process are discussed. Using Harvey and other methods to optimize the minimum energy crossover (MECP), the possibility of the “inter system channeling” (ISC) between different potential energy surfaces in the reaction of Th and C2H4 is further discussed. In the end, we make a brief discussion on the frontier molecular orbital MECP2, which can be used as a guide for further theoretical research and experiment.